(A) Field of the Invention
The invention relates to the herbal extract having anti-viral activity. More specifically, it relates to the herbal extract produced by extracting privet fruit, sealwort, agrimonia, steamed glutinous rehmannia or the mixture thereof, with a low polar solvent, and to the method for in vitro antagonizing virus by contacting the herbal extract with viruses.
(B) Description of Related Art
Viruses introduce a variety of diseases by spreading through different infection routes, such as air, droplet, or contact. Every year in spring and autumn, Taiwan is attacked by infectious diseases of digestive tract, which considerably affect the islands and threat the public, especially infants and children. Enteroviruses infect persons who make contact with oral or nasal secreta, excrement, or spray of patients. They are subject to spreading in places where high population density is available. Since no specific treatment has been found to conquer enterovirus infection, doctors often employ supporting treatment to defend from viruses. In addition, there exist a vast variety of changeable enteroviruses. Therefore, even if a person has been infected by a certain type of enterovirus, he or she obtains no life-long immunity to other types. The method to prevent from being infected by viruses is to wash hands whenever necessary, live in a clean and ventilated house, wear a respirator, and keep from contacting with infected persons.
The U.S. Pat. No. 6,214,350 relates to aqueous extracts from fruits of Ligustrum lucidum and/or L. japonicum. It reveals a method to prepare said extracts in the following steps: Fruits of Ligustrum lucidum and/or L. japonicum or mixture thereof are exposed to water to remove insoluble contents thereof; aqueous solution is acidified to get acid precipitate, which is then purified. Said patent reveals that said aqueous extracts from fruits of Ligustrum lucidum and/or L. japonicum may be used to treat Hepatitis B (HBV), Hepatitis C(HCV), and Human Immunodeficiency Virus (HIV).
The U.S. Pat. No. 5,888,527 relates to aqueous extracts from tea. Said extracts that contain active catechin and black tea polyphenols are used to antagonize fungus, bacteria, and influenza virus.
Until now, no publicized document has been found on how to obtain extracts from fruit of Ligustrum lucidum by using low polarity solvents, or how to use such extracts to antagonize viruses, especially enteroviruses, a subgroup of picornaviruses. In addition, since water is a high polarity substance and different viruses act differently and are considerably specific to medicines, none of the previous technologies illustrated hereinabove may be extended to either the concept or the implementation of the present invention. Moreover, there exists demand to prevent or treat viral diseases or symptoms with herbal medicines.